This angle connector (11 53 1 711 385) fits where the drain plug normally goes, there is an O ring on it that will get distorted or fall out upon removal. BMW O ring 17 11 1 711 987 should fit.

Mark.

Oh oh, I got the o-ring, and under careful inspection the angle connector is cracked and this explains the leak. O-ring isn't going to help me, I need the angle connector/o-ring assembly - part # comes with the hose as well.
This is after draining all the fluid from the radiator and block - anyone know where to get this part in a hurry (now) in the GTA?